This invention relates to a chassis for video tape recorders (hereinafter referred to as VTR.
The chassis for VTR is designed to carry various precision machine components for driving VTR such as a guide drum (cylinder) with magnetic head, capstan roller magnetic tape cassette, etc., and the accessory parts thereof, and it is also provided with the protuberances and recessions or openings for supporting and fixing these carried elements as well as the walls, grooves and holes for guiding the movements of the movable component parts. For producing a chassis, generally either of the following two systems have been employed: a chassis blank is first molded by aluminum die casting, and then the chassis blank if subjected to precision working, with the metal protuberances being caulked or by fixing screw means, or a steel sheet is press worked and then the metal protuberances are caulked or fixed by screwing. Therefore, no matter which system is employed, the production cost is high because of the long manufacturing process. Also, according to these system, the produced chassis is heavy because of use of metal, and if a reduction in the weight is attempted by decreasing the wall thickness, there is a lowering of rigidity or reduction of the production yield. Thus, there was a certain limitation to the efforts for weight reduction according to the prior art.
One of effective means for realizing a weight reduction and improvement of the production process is an adoption of integral molding by use of plastics. Generally, however, use of plastics results in a product which tends to suffer deformation with the lapse of time as well as creep deformation, and further, since high dimensional precision is required and also loading weight is high in the case of the chassis for VTR, many difficulties remain to be surmounted for adaptation of plastics of such chassis. Although U.S. Pat. No. 3,899,795 proposes a plastic-made chassis for a so-called cassette tape recorder, no commercial adaptation of plastic to the chassis for VTR has yet been realized due to the fact that the chassis for VTR is greater in volume than the chassis for cassette tape recorder and hence more liable to suffer deformation in use.